A large and growing literature links exposure to chemicals during specific periods of fetal development with: adverse birth outcomes, such as preterm delivery and low birthweight;childhood illnesses, such as neurodevelopmental disorders and cancer;and later onset of adult disorders, such as diabetes and cardiovascular disease. In addition, large national biomonitoring studies are reporting nearly ubiquitous exposure to numerous environmental contaminants in the US population, raising the question of how exactly people are being exposed and what are the implications. Furthermore, studies of mid-gestation pregnancies confirm that the placenta does not act as a barrier to exogenous chemicals and also indicate that the fetus - at a time when it lacks detoxifying mechanisms - may experience higher levels of exposure than the mother. We propose to assemble a new, integrated, multidisciplinary group of researchers from the biological, clinical and epidemiologic sciences into the UCSF Pregnancy Exposures and Environmental Contaminants Formative Center. The theme of the PEEC Formative Center is to advance our understanding of how exposure to environmental chemicals affects early development using an innovative multidisciplinary approach that 1) integrates research on sources and exposures to environmental chemicals during pregnancy with basic biological research on how chemical exposures may disrupt early development and 2) translates these scientific findings to healthcare providers, policy makers and community groups in order to improve clinical care and promote policies that prevent prenatal exposures to harmful chemicals. Our long term goals are to develop novel techniques for early identification of harmful exposures, to devise novel strategies for the prevention of environmentally mediated diseases, to develop new relationships with health care professionals and community groups to transmit scientific information about the effect of environmental contaminants on early development, and to inspire career choice and advocacy in this important area of prenatal environmental health and research.